+----------------------------+ +----------------------------+
| ID | Date | | ID | Date |
+----------------------------+ +----------------------------+
| 1 | 2017-06-13 22:10:01 | | 1 | 2017-06-20 22:10:50 |
+----------------------------+ +----------------------------+
| 2 | 2017-06-14 13:22:20 | | 2 | 2017-06-23 22:10:55 |
+----------------------------+ +----------------------------+
| 3 | 2017-06-16 22:10:01 | | 3 | 2017-06-27 22:10:35 |
+----------------------------+ +----------------------------+
| 4 | 2017-07-04 22:10:07 |
+----------------------------+
I have 2 tables, same columns. The first one will be a sample, having entries on a week basis, each with 1-minute difference (10 080 entries in total). While the other one gets new values everytime (1 min), indefinitely.
What I try to do is compare each new entry with an entry from the first database. But I want to compare depending on weekday and time (same hour and same minutes).
For instance, an entry on Monday at 11:00 (whatever month, day and year) should be compared with one on Monday at 11:00 from the sample database.
What I want to do is get the number of the entry from sample database when it's the same weekday as the entry in the second table:
2017-06-20 22:10:50 should return 1.
2017-06-23 22:10:55 should return 3.
2017-06-27 22:10:35 should return 1.
2017-07-04 22:10:07 should return 1.
Edit2:
I think you may understand things better when I explain the purpose of the two tables.
The real tables in my database have more columns: sensors' id and their value.
The first table, sample table, will have data received for a whole week. It's used as a reference.
The second table receives data every minute, when one gets in it should be compared with a record in the sample table to detect if values are equals or not(anormal value).
So I want to detect abnormal values by comparing with a record of same weekday, same hours and minutes.
Well I think I found what I was looking for. This is a useful link : Get month from DATETIME in sqlite
Here is the way to match timestamps :
//Matching weekday
select * from table where strftime('%w', Date) = '0';
//Matching weekday + hours and minutes
select * from table where strftime('%w', Date) = '0' and strftime('%H:%M', Date) = '22:10';
Thank you guys anyway.
Related
I need to get the time difference between two dates on different rows. This part is okay but I can have instances of the same title. A quick example which will explain things some more.
Lets say we have a table with the following records:
| ID | Title | Date |
| ----- | ------- |--------------------|
| 1 | Down |2021-03-07 12:05:00 |
| 2 | Up |2021-03-07 13:05:00 |
| 3 | Down |2021-03-07 10:30:00 |
| 4 | Up |2021-03-07 11:00:00 |
I basically need to get the time difference between the first "Down" and "Up". So ID 1 & 2 = 1 hour.
Then ID 3 & 4 = 30 mins, and so on for the amount of "Down" and "Up" rows there are.
(These will always be grouped together one after another)
It doesn't matter if the results are seperate or a SUM of all the differences.
I'm trying to get this done without a temp table.
Thank you.
This can be done using analytical functions, the availability of which will be determined based on your sql engine. The idea is to get the next value in the same row as the one you need to calculate the diff/sum
In the case above it would look some thing like below
SELECT
id ,
title,
Date as startdate,
LEAD(Date,1) OVER (
ORDER BY id
) enddate
FROM
table;
Once you have it on the same row, you can carry out your time difference operation.
I've been searching for quite a while and can't find an answer to this question:
I have a PostgreSQL table that is staged the following way:
Start Date | End Date | Name | Team
-----------+------------+---------+------
2017-10-01 | 2017-10-10 | Person | 1
And what I would like to is have each row a day between the start date and end date with the corresponding name and team of the person:
Date | Name | Team
------------+---------+-------
2017-10-01 | Person | 1
------------+---------+-------
2017-10-02 | Person | 1
------------+---------+-------
2017-10-03 | Person | 1
Is it even possible to do this with PostgreSQL? I'm currently running PostgreSQL 9.3.
You can use generate_series() for that:
select t.dt::date, p.name, p.team
from person p, generate_series(p.start_date, p.end_date, interval '1' day) as t(dt)
order by t.dt::date;
I don't have 9.3 around any more, but I think that should also work with that old version.
In my code using SQL Server, I am comparing data between two months where I have the exact dates identified. I am trying to find if the value in a certain column changes in a bunch of different scenarios. That part works, but what I'd like to do is make it so that I don't have to always go back to change the date each time I wanted to get the results I'm looking for. Is this possible?
My thought was that adding a WITH clause, but it is giving me an aggregation error. Is there anyway I can go about making this date problem simpler? Thanks in advance
EDIT
Ok I'd like to clarify. In my WITH statement, I have:
select distinct
d.Date
from Database d
Which returns:
+------+-------------+
| | Date |
+------+-------------|
| 1 | 01-06-2017 |
| 2 | 01-13-2017 |
| 3 | 01-20-2017 |
| 4 | 01-27-2017 |
| 5 | 02-03-2017 |
| 6 | 02-10-2017 |
| 7 | 02-17-2017 |
| 8 | 02-24-2017 |
| 9 | ........ |
+------+-------------+
If I select this statement and execute, it will return just the dates from my table as shown above. What I'd like to do is be able to have sql that will pull from these date values and compare the last date value from one month to the last date value of the next month. In essence, it should compare the values from date 8 to values from date 4, but it should be dynamic enough that it can do the same for any two dates without much tinkering.
If I didn't misunderstand your request, it seems you need a numbers table, also known as a tally table, or in this case a calendar table.
Recommended post: https://dba.stackexchange.com/questions/11506/why-are-numbers-tables-invaluable
Basically, you create a table and populate it with numbers of year's week o start and end dates. Then join your main query to this table.
+------+-----------+----------+
| week | startDate | endDate |
+------+-----------+----------+
| 1 | 20170101 | 20170107 |
| 2 | 20170108 | 20170114 |
+------+-----------+----------+
Select b.week, max(a.data) from yourTable a
inner join calendarTable b
on a.Date between b.startDate and b.endDate
group by b.week
dynamic dates to filter by BETWEEN
select dateadd(m,-1,dateadd(day,-(datepart(day,cast(getdate() as date))-1),cast(getdate() as date))) -- 1st date of last month
select dateadd(day,-datepart(day,cast(getdate() as date)),cast(getdate() as date)) -- last date of last month
select dateadd(day,-(datepart(day,cast(getdate() as date))-1),cast(getdate() as date)) -- 1st date of current month
select dateadd(day,-datepart(day,dateadd(m,1,cast(getdate() as date))),dateadd(m,1,cast(getdate() as date))) -- last date of the month
Ok, I have a tough SQL query, and I'm not sure how to go about writing it.
I am summing the number of "bananas collected" by an employee within the last X days, but what I could really use help on is determining X.
The "last X days" value is defined to be the last 100 days that the employee was NOT out due to Purple Fever, starting from some ChosenDate (we'll say today, 6/24/14). That is to say, if the person was sick with Purple Fever for 3 days, then I want to look back over the last 103 days from ChosenDate rather than the last 100 days. Any other reason the employee may have been out does not affect our calculation.
Table PersonOutIncident
+----------------------+----------+-------------+
| PersonOutIncidentID | PersonID | ReasonOut |
+----------------------+----------+-------------+
| 1 | Sarah | PurpleFever |
| 2 | Sarah | PaperCut |
| 3 | Jon | PurpleFever |
| 4 | Sarah | PurpleFever |
+----------------------+----------+-------------+
Table PersonOutDetail
+-------------------+----------------------+-----------+-----------+
| PersonOutDetailID | PersonOutIncidentID | BeginDate | EndDate |
+-------------------+----------------------+-----------+-----------+
| 1 | 1 | 1/1/2014 | 1/3/2014 |
| 2 | 1 | 1/7/2014 | 1/13/2014 |
| 3 | 2 | 2/1/2014 | 2/3/2014 |
| 4 | 3 | 1/15/2014 | 1/20/2014 |
| 5 | 4 | 5/1/2014 | 5/15/2014 |
+-------------------+----------------------+-----------+-----------+
The tables are established. Many PersonOutDetail records can be associated with one PersonOutIncident record and there may be multiple PersonOutIncident records for a single employee (That is to say, there could be two or three PersonOutIncident records with an identical ReasonOut column, because they represent a particular incident or event and the not-necessarily-continuous days lost due to that particular incident)
The nature of this requirement complicates things, even conceptually to me.
The best I can think of is to check for a BeginDate/EndDate pair within the 100 day base period, then determine the number of days from BeginDate to EndDate and add that to the base 100 days. But then I would have to check again that this new range doesn't overlap or contain additional BeginDate/EndDate pairs and add, if so, add those days as well. I can tell already that this isn't the method I want to use, but I can't wrap my mind quite around how exactly what I need to start/structure this query. Does anyone have an idea that might steer me in the correct direction? I realize this might not be clear and I apologize if I'm just confusing things.
One way to do this is to work with a table or WITH CLAUSE that contains a list of days. Let's say days is a table with one column that contains the last 200 days. (This means the query will break if the employee had more than 100 sick days in the last 200 days).
Now you can get a list of all working days of an employee like this (replace ? with the employee id):
WITH t1 AS
(
SELECT day,
ROW_NUMBER() OVER (ORDER BY day DESC) AS 'RowNumber'
FROM days d
WHERE NOT EXISTS (SELECT * FROM PersonOutDetail pd
INNER JOIN PersonOutIncidentID po ON po.PersonOutIncidentID = pd.PersonOutIncidentID
WHERE d.day BETWEEN pd.BeginDate AND pd.EndDate
AND po.ReasonOut = 'PurpleFever'
AND po.PersonID = ?)
)
SELECT * FROM t1
WHERE RowNumber <= 100;
Alternatively, you can obtain the '100th day' by replacing RowNumber <= 100 with RowNumber = 100.
I don't think there is an elegant way to do this, but here goes. Database contains 5000 records with timestamps of 2 years. I need to pull the records under each day of the year.
So it looks like..
09/09/2009 - record938, record2, record493
09/10/2009 - record260, record485, record610
...etc
I cannot use GROUP BY. There are duplicates and that's OK. I need to show them.
Is this possible? PHP/MySQL?
One way of doing it is looping through every day of the year and doing a query with "WHERE DAY(created_at)..." but obviously this isn't elegant.
HOW can I do this? I posted this question before without a satisfactory answer (answer was what I just stated above)
MySQL has the group_concat() aggregate function:
SELECT date(rec_time), group_concat(rec_id)
FROM records GROUP BY date(rec_time);
Will return all rec_id values from table joined by commas, for each date. If you want a separator other than , use group_concat(some_column SEPARATOR '-')
Example
For example if your table looks like:
+--------+---------------------+
| rec_id | rec_time |
+--------+---------------------+
| 1 | 2009-11-28 10:00:00 |
| 2 | 2009-11-28 20:00:00 |
| 3 | 2009-11-27 15:00:00 |
| 4 | 2009-11-27 07:00:00 |
| 5 | 2009-11-28 08:00:00 |
+--------+---------------------+
Then this query gives:
mysql> SELECT date(rec_time), group_concat(rec_id)
-> FROM records GROUP BY date(rec_time);
+----------------+----------------------+
| date(rec_time) | group_concat(rec_id) |
+----------------+----------------------+
| 2009-11-27 | 3,4 |
| 2009-11-28 | 1,2,5 |
+----------------+----------------------+
Caveat
Beware that the result is limited by the group_concat_max_len system variable, which defaults to only 1024 bytes! To avoid hitting this wall, you should execute this before running the query:
SET SESSION group_concat_max_len = 65536;
Or more, depending on how many results you expect. But this value cannot be larger than max_allowed_packet